New vat dyestuffs



Patented Nov. 4, 1930 UNITED. STATES PAUL NAWIASKY Ann ARTUR. KRAUSE, or nonwfesnarnmon 'rrm nnmn, G R;

MANY, ASSIGNORS T0 GENERAL AnILrnEwoRKs, me, or EvqYongi-n'. a con-.

PORATION OF DELAWARE NEW vmnnsmsm I i No Drawing. Application filed March 23, 1928, Serial ..124,f; ,aa Germany March.30, 192:7.,

other dyestuffs. The aforesaid products may i be purified if necessary, for example, by treatment with oxidizing agents, or by recrystallization or by fractional precipitation from their solutions in concentrated sulfuric acid.

The following examples will further illustrate how the said invention may becarried into practical effect but the invention is not limited thereto. The parts are by weight.

Example 1 10 parts of anthrapyrimidine 0f the formula:

obtainable by the action ofv formamide on a-aminoanthraquinone, are introduced at 130 centigrade into a melt prepared by heating 100 parts of caustic-potash and 100 parts of ethyl alcohol. The temperature is then raised 130140 centigrade and there maintained until the formation of the dyest'uif is complete. The red-brown melt is poured into water, the leuco compound is oxidized with air, and the dyestuff is further treated in the usual manner. The yellowbrown product gives brown dyeings on cotton from a brown vat, the color changing on exposure to the air, to a'yellow with greenish tinge, which is fast to chlorine and soap. The dyestuff may be purified, either before or after application to the fibre, by treatment with oxidizing agents as for example by heating with hypochlorite solution. It dissolves with great difficulty in organic solvents, and furnishes yellow-green needles on recrystallization from trichlorbenzene.

' Example 2 of the formula: V

I /CH| J are introduced at centigrade into a'melt. prepared by heating 100'parts of caustic potash and 100 parts of ethyl'alcohol. The temperature is then raised to centigrade until the formation of the dyestulf is com-' plete, andthe further treatment is carried on i as described in Example 1; 'The dyestufli' gives brown dyeings on cotton, from'a vat of the same color. On exposure to t e air, th 2- 1 color changes to very fast lemon-yellow. The

dyestuff is very sparingly soluble in trichlor- V benzene from which it crystallizes out in yellow-green needles. Purification may be efs fected for example byv treatment with izing agents as in Example 1.

What we claim is: I i 'ly A process for the productionof new condensation products, which consists in oxid treating anthrapyrimidines with alkaline condensing agents.

2. A process for the production of new condensation products, which consists in treating anthrapyrimidines with alkaline condensing agents and'purifying by treat ment with an oxidizing agent.

3. The process for the production of a yellowvat dyestuif, which consists in treating anthrapyrimidine in an alcoholic caustic potash melt.

4E. As new articles of manufacture, the vat I dyestuffs which I dye cotton brown shades from vats of the same color, the color of the dyeings changing to yellow Witha reenish. tinge on exposure to air, the dyestus being obtainable by treating anthrapyrimidifies .With alkaline condensing agents. I I j 5. As ELIIGWBJTfiClQOf manufacture thevat ejdyestl'rfi, ayes cotton'brown f x emzayat ,-0f the same colorgthe color of the dyeing {changing to yellow-with a greenishftinge on In' testimony whereof e g ourihan ds 1 )abl bytieatingeahthrapyrimidineiiiitheufl:' i5

eoholic caustic potashmeltr T I have heyelint'qiei ,7 ,7 PAUL NAWiAS Iiig "g 

